Verb phrases convey when an action or condition happens regularly or over a course of time. The most basic sentence in the English language contains a subject (noun) and a verb: "Joe danced." A verb phrase expands this to convey a sense of time or some other relationship.
Verb phrases, consisting of main and helping verbs, can be up to four words long. "When we arrived, Joe was dancing with Marla." In this instance, "was dancing" is the verb phrase. "Joe would have danced with Marla if she hadn't stood him up." Here, "would have danced" is the verb phrase.